When retry flag is set, the hmac is generated based on the previous n…

…once, but the hmac has to be regenerated since the date changes

README.md

@@ -1,16 +1,19 @@
 # Modulr Finance HMAC
 
-### [ModulrAuthHeaderExample.java] (https://github.com/Modulr-finance/modulr-hmac/blob/master/ModulrAuthHeaderExample.java)
-This class provides a Java example of generating HMAC Signature headers for use with Modulr API calls.
+### Samples
+Samples directory contain sample code for the following languages:
+- Java
 
 ### [io.swagger.client.auth.ApiKeyAuth.java] (https://github.com/Modulr-finance/modulr-hmac/blob/master/io/swagger/client/auth/ApiKeyAuth.java)
 This class provides a drop in replacement for the same file generated from Swagger.io Java client generation. This assumes you set ApiKey to your Modulr issued API Key and ApiKeyPrefix to your Modulr issued API secret in io.swagger.client.Configuration. For example;
 
 ```java
-public static void main(String[] args) throws ApiException {
-	Configuration.getDefaultApiClient().setApiKey("<Your API Key>");
-	Configuration.getDefaultApiClient().setApiKeyPrefix("<You API Secret>");
-	TransactionsApi api = new TransactionsApi();
-	System.out.println(api.getTransactionsUsingGET("A02017NU",0,25));
+class ModulrApiAuth {
+    public static void main(String[] args) throws ApiException {
+        Configuration.getDefaultApiClient().setApiKey("<Your API Key>");
+        Configuration.getDefaultApiClient().setApiKeyPrefix("<You API Secret>");
+        TransactionsApi api = new TransactionsApi();
+        System.out.println(api.getTransactionsUsingGET("A02017NU",0,25));
+    }
 }
 ```

samples/java/src/main/java/com/modulr/api/ModulrApiAuth.java

@@ -20,7 +20,7 @@ public class ModulrApiAuth {
     private Date date;
     private Boolean retry = false;
 
-    private String lastGeneratedHmac;
+    private String lastUsedNonce;
 
     public ModulrApiAuth(String token, String secret, String nonce) {
         this.token = token.trim();
@@ -48,15 +48,14 @@ public Map<String, String> getApiAuthHeaders() {
     public String generateHmac() throws SignatureException {
         final String hmac;
         if (this.retry) {
-            hmac = this.lastGeneratedHmac;
+            this.nonce = this.lastUsedNonce;
         } else {
-            validateFields();
-            String data = String.format("date: %s nx-mod-nonce: %s", getFormattedDate(this.date), this.nonce);
-            hmac = calculateHmac(data);
-            this.lastGeneratedHmac = hmac;
+            this.lastUsedNonce = this.nonce;
         }
 
-        return hmac;
+        validateFields();
+        String data = String.format("date: %s nx-mod-nonce: %s", getFormattedDate(this.date), this.nonce);
+        return calculateHmac(data);
     }
 
     public String getNonce() {
@@ -88,8 +87,7 @@ public Boolean getRetry() {
     }
 
     public void setRetry(Boolean retry) {
-        if (this.lastGeneratedHmac != null)
-            this.retry = retry;
+        this.retry = retry;
     }
 
     private String formatAuthHeader(String token, String signature) {